Virtual image display device and head mounted display using same

Abstract

A virtual image display device has a function of projecting a prescribed virtual image video within a visual field of a user and detects an actual visual recognition distance from the user to an object relating to a visually recognized object at which the user is gazing. A virtual image light generating unit has a function of generating a plurality of virtual image lights independent of each other and a virtual-image-light transmitting and projecting unit that has a function of transmitting and projecting the virtual image light to left and right eyes of the user through substantially the same optical path to allow a prescribed virtual image video to be visually recognized at a prescribed position within the visual field of the user. Additionally, a virtual-image visual recognition distance control unit that has a function of performing variable control of a visual recognition distance of a virtual image.

The invention claimed is: 
     
       1. A virtual image display device having a function of projecting a prescribed virtual image video within a visual field of a user, comprising:
 a visual recognition distance detector configured to detect an actual visual recognition distance from the user to an object relating to a visually recognized object at which the user is gazing or at least a portion of a plurality of objects within the visual field; 
 a virtual image light generator configured to generate a plurality of virtual image lights independent of each other and convert a polarization direction of the virtual image light; 
 a virtual-image-light transmitter and projector configured to transmit and project the virtual image light to left and right eyes of the user through substantially the same optical path to allow a prescribed virtual image video to be visually recognized at a prescribed position within the visual field of the user; and 
 a virtual-image visual recognition distance controller configured to perform variable control of a visual recognition distance of a virtual image visually recognized by the user by using the plurality of projected virtual image lights; 
 wherein the virtual image light generator is further configured to: 
 alternately switch different virtual image lights, which are generated on a basis of the visual recognition distance, at a frame rate, and 
 convert each polarization direction of the different virtual image lights which are switched alternately at the frame rate. 
 
     
     
       2. The virtual image display device according to  claim 1 , wherein the visual recognition distance detector is configured to detect visual line inclination angles of the left and right eyes from convergence amounts at centers of pupils of the left and right eyes of the user and calculating the actual visual recognition distance from the visual line inclination angles by using a prescribed Relational Formula. 
     
     
       3. The virtual image display device according to  claim 1 , wherein the visual recognition distance detector is configured to specify the object at which the user is gazing among the plurality of objects within the visual field of the user from the visual line inclination angles of the left and right eyes detected from convergence amounts at centers of pupils of the left and right eyes of the user and detecting an actual distance from the user to the gazing object of the user by using a prescribed distance measuring unit. 
     
     
       4. The virtual image display device according to  claim 1 , wherein the virtual-image visual recognition distance controller is configured to match the visual recognition distance of the visually-recognized virtual image of the user with the actual visual recognition distance detected by the visual recognition distance detector. 
     
     
       5. The virtual image display device according to  claim 1 , wherein the virtual image light generator and the virtual-image-light transmitter and projector are configured to project the first and second virtual image lights having different visual recognition distances so as to be correctly projected and superimposed and visually recognized as viewed from the user, and
 wherein the virtual-image visual recognition distance controller is configured to perform variable control of the visual recognition distance of the visually-recognized virtual image of the user at an arbitrary distance between the visual recognition distances of the first and second virtual image lights by performing variable control of the luminance apportionment of the respective two types of the virtual image lights for each display video item by using a prescribed Relational Formula. 
 
     
     
       6. The virtual image display device according to  claim 5 , wherein the first and second virtual image lights have polarization directions that are at least substantially perpendicular to each other, and the optical paths of the first and second virtual image lights are separated or combined by a polarizing beam splitter arranged in the virtual image light generator. 
     
     
       7. The virtual image display device according to  claim 1 ,
 wherein the virtual image light generator is configured to generate first and second virtual image lights independent of each other, 
 wherein the virtual-image-light transmitter and projector is configured to project the first virtual image light only to the right eye of the user and project the second virtual image light only to the left eye of the user, and 
 wherein the virtual-image visual recognition distance controller is configured to perform the variable control of the visual recognition distance of the virtual image by in-plane shifting a position of each display video item within the virtual image video visually recognized by the user by using the first and second virtual image lights by a relative distance corresponding to a binocular parallax according to a prescribed visual recognition distance. 
 
     
     
       8. The virtual image display device according to  claim 7 , wherein the first and second virtual image lights have polarization directions that are at least substantially perpendicular to each other, and the optical paths of the first and second virtual image lights are separated or combined by a polarizing beam splitter arranged in the virtual image light generator. 
     
     
       9. The virtual image display device according to  claim 1 , wherein the virtual-image-light transmitter and projector is configured to include one or a plurality of laminated light-guiding plates, and each of the plurality of light-guiding plates is provided with an incident hologram which allows a light wave to be incident on each of the light-guiding plates and an outgoing hologram which emits a light wave traveling in the light-guiding plate to the outside. 
     
     
       10. A head mounted display device having a virtual image display device having a function of projecting a prescribed virtual image video within a visual field of a user,
 wherein the virtual image display device comprises: 
 a visual recognition distance detector configured to detect an actual visual recognition distance from the user to an object relating to a visually recognized object at which the user is gazing or at least a portion of a plurality of objects within the visual field; 
 a virtual image light generator configured to generate a plurality of virtual image lights independent of each other and converting polarization direction of the virtual-image-light; 
 a virtual-image-light transmitter and projector configured to transmit and project the virtual image light to left and right eyes of the user through substantially the same optical path to allow a prescribed virtual image video to be visually recognized at a prescribed position within the visual field of the user; and 
 a virtual-image visual recognition distance controller configured to perform variable control of a visual recognition distance of a virtual image visually recognized by the user by using the plurality of virtual image lights; 
 wherein the virtual-image-light generator is further configured to: 
 alternately switch different virtual image lights, which are generated on a basis of the visual recognition distance, at a frame rate; and 
 convert each polarization direction of the different virtual image lights which are switched alternately at the frame rate.